F-Droid

don't know if this is an appropriate community

I don't particularly like this application, but my whole family uses and they simply won't use any foss alternative I've proposed so far.

I'm even thinking about joining them.

I only need audio, no video calls, no file transfers.

ETA: what free droid apps can do simply that, not needing for me to provide a phone number or my current location / country?